Monday, April 27, 2009

Going Nuclear

Living under the specters of global warming, as well as economical and political instability, out planet is evermore hungry for energy. So let’s look at the options. Fossil fuels, a concentrated form of solar energy, come from plants which became fossilized over millions of years and formed oil, coal and gas. In the process, solar energy was concentrated. Burning coal produces twice the energy of burning wood. Oil and gas are about twice the energy density of coal. All fossil fuels, when burned, produce greenhouse gases. Moreover, recent estimations of oil reserves predict an oil crunch in 30 years, if current trends of consumption persist. The discovery of new oil fields will not save us from the inevitable crunch because increased consumption will outstrip any foreseeable new supply.Being addicted to oil means we go turkey in less than a generation, unless we kick the habit now.

Renewables, such as wind and sunlight, are on the other side of the scale, i.e. they are less energy dense than wood by a factor of 10 to 50. The amount of sunlight that falls on a square meter of earth is barely enough to power one 100watt light bulb. To implement solar energy power stations on an industrial scale requires huge amounts of land. Covering every rooftop with solar panels would probably get enough electricity for our indoor supply (approx. less than 10% of national total), and only during daytime. Storing solar energy in batteries so it can be used during nighttime creates the vexing problem of waste managing the highly toxic materials in batteries.

Wind farms do not fare any better. Covering hundreds of acres with 65-meter structures produces unpredictable electricity output that is difficult to integrate in the national grid. Wind not only comes and goes as it pleases, but is stronger on places that need massive investment to connect to the grid (mountains, islands), and mainly blows during seasons of low demand in electricity (autumn and spring). Biofuels, once heralded as the magic bullet to save the planet, has been called by Jean Ziegler, UN’s raporteur on food, “a crime against humanity”. Fermenting double digit percentage points of the world’s food output to produce ethanol has caused steep rises in food prices and consequently hunger, riots and deaths. To conclude, subsidizing so-called “green technologies” makes perfect media sense but very little economic sense.

Let’s now look at nuclear. The energy density for uranium compared to coal is 2 million! That means that one kilogram of uranium gives you 2 million times as much energy as a kilogram of coal. You can run Athens for a week with a lump of uranium you can hold in one hand. The comparison with coal plants is even more flabbergasting. To fuel a 1000 MW coal plant you need massive and endless trainloads of coal feeding it daily. To fuel a 1000 MW nuclear reactor you need an infinitesimal fraction of that input in the form of fuel rods that are mildly radioactive and can be handled with gloves. In their four-and-a-half years lifecycle these fuel rods produce zero carbon emissions. By comparison, the same coal plant over the same period will have spewed 3 million tons of carbon dioxide in the atmosphere.

Resistance to nuclear energy rests on three issues: danger of meltdown and/or explosion, security issues pertaining to theft of atom bomb materials by terrorist organizations and nuclear waste disposal. So could a nuclear reactor explode? What about Chernobyl? The danger for explosion, or meltdown, is directly related to the fraction of radioactive material that takes part in the nuclear reactions in the nuclear plant. There are two types of uranium, U-238 (with 238 neutrons) which makes 99.3 percent of the natural ore and U-235. The former sheds two protons every now and then over a 5 billion year period, and is less harmful than your TV set. The latter is the powerhouse. It can split and create massive amounts of energy. But U-235 constitutes only 0.7 percent of the natural ore. Being so sparse it cannot undergo a natural “chain reaction”. In order to obtain a larger fraction of U-235, natural core uranium is “enriched”. This is extremely difficult. You need a huge factory to do it and various techniques such as running the natural ore through magnetic fields and whipping it in centrifuges. There are different kinds of enrichment. To produce the nice calm chain reactions in a nuclear reactor you need to enrich U-235 from 0.7 to 3 percent. To enrich to bomb-grade material you have to enrich to 90 percent. This takes a lot of time and effort and specially designed reactors that have dual-use, civil and military. A strictly civil-use nuclear plant is inherently safe and cannot explode.Chernobyl did not explode. The cooling system failed and tore apart the reactor casing resulting in radioactive gases released in the atmosphere. It was because soviet-era reactors did not have the safety feature of reactor casing as western reactors did. Since those days, western reactors have become even safer, with automatic shut-off mechanisms for controlled nuclear reactions, should any accident occur. Earthquakes are not a problem for modern construction engineers who can build safe structures able to withstand the most violent tremors.

The fear of proliferation of nuclear fission by-products, such as plutonium, which could be stolen by terrorists and used in terrorist activities, prompted the Carter administration in 1976 to pass a bill forbidding nuclear fuel recycling. However, to build a bomb you need to enrich uranium at 90%, which is a very difficult process. That is why, for example, one should not worry too much that the Iranians will get to it quickly. The stuff enriched in a civil nuclear plant is not even good for a firecracker. As experience has shown, the bad guys got their nuclear technology from Pakistan and North Korea, not by stealing materials from western, or Soviet, civil nuclear plants.

As for waste, there is no such thing as “nuclear waste”. Nearly all the material in a spent fuel rod is recyclable or easily handled. Ninety-five percent of a spent fuel rod is harmless, natural, U-238 that can be put back to where it came from. The rest is fissionable U-235 (1%), various fission products that can be used in nuclear medicine (2%), a residue of “minor actinides” (2%) - that includes plutonium (1%) - that can also be recycled. The French have virtually complete recycling. All of France’s nuclear waste from 25 years of producing 75 percent of its electricity is stored beneath the floor of a room at Le Hague. The lifetime output of each French citizen would fit in a beer can.

Nuclear power could be humanity’s greatest hope for the future. Currently, to construct a nuclear plant costs 2,000 to 5,000 USD per KW/h. This means that a 1000 MW reactor would cost anything between 2 and 5 billion USD. If this sounds a lot, remember that the Greek government gave the banks a fat cheque of taxpayers’ money amounting to 35 billion USD. The same money could have bought us all the energy we need for the next century, save the environment, create jobs, rejuvenate the economy, and promote science and Greece’s geopolitical role in Eastern Mediterranean as a power of peace and prosperity. As for the fuel, uranium is ubiquitous and currently costs 59 USD per pound.

The Earth’s core is hot because of uranium’s natural nuclear decay. And because of the small percentage of U-235 in the natural ore, planet Earth is in no danger of exploding into space. We tap this nuclear energy with geothermal plants and call it “geothermal”. However, by simply taking the uranium ore out of the ground and placing it in a nuclear reactor we can multiply the energy efficiency of the same process by millions of times, providing massive amounts of electricity with zero greenhouse emissions. Investing in nuclear plants will not only solve our country’s energy problems and make us energy independent, but will also provide jobs for construction workers and highly skilled scientists and engineers. The majority of the Greek public is currently against nuclear power because they are either misinformed or plainly uninformed. And yet, while neighboring countries are set to construct nuclear plants within the next 20 years, Greece desperately needs visionary politicians to take up the nuclear agenda. The debate must open.

This article was commissioned for the Athens News, published Nov. 28th